title: [Influence of visual stimulation on cerebral blood flow and visual evoked potentials in children with migraine with visual aura].
abstract: BACKGROUND
  Visual aura is the most common type of migrainous aura. It may occur as a single symptom or precede sensory or speech disturbances. Aura symptoms and order of their appearance may result from propagation of spreading depression phenomenon. Vascular disorders observed during migraine with aura attacks are probably secondary to neuronal changes. Simultaneous registration of cerebral bioelectric activation and changes evoked in cerebral circulation enables their objective estimation, detection of correlation and better understanding of migraine with aura pathogenesis. Studies with transcranial Doppler revealed impaired cerebrovascular response to various stimulations in migraine, especially migraine with aura patients. Combination of Doppler examination with registration of visual evoked potentials (VEP) enables estimation on neurovascular coupling.
  
  
  OBJECTIVE
  Estimation of cerebrovascular response to visual stimulation in migraineurs with visual aura. Examination of correlation between cerebral blood flow and VEP parameters.
  
  
  METHODS
  50 children at the age range 8-18 years, 8 with migraine with visual aura, 9 with visual and sensory aura, 8 with visual, sensory and dysphasic aura and 25 children from control group. Examination of cerebral blood flow parameters was performed with transcranial Doppler, with the use of continuous monitoring, enabling performance of simultaneous record. ing from vessels of both hemispheres. Systolic (SV), end-diastolic (EDV), mean (MV) velocities and pulsatility (PI) and resistive indexes (RI) were analyzed. Parameters of cerebral blood flow were recorded in middle cerebral arteries, at rest (1 measurement), during visual stimulation (2, 3 measurement) and directly after the end of the stimulation (4 measurement). Black and white checkerboard pattern rebersal was visual stimulator and during stimulation VEP were registered. N75, P100, N135 latencies and N75/P100, P100/N135 amplitudes were analyzed. Moreover correlation between visually evoked changes in cerebral blood flow (2-1 measurement) and VEP values was examined.
  
  
  RESULTS
  Statistically significant differences in EDV and MV were found between controls and migraineurs with aura. In response to visual stimulation significant differences in cerebral blood flow velocities (SV, EDV, MV) were found and most often were observed direct after the beginning of the stimulation, however they did not differ significantly between the groups. Interactions between group and time was also not found in the following analyzed groups: migraine with visual, sensory and visual, sensory, dysphasic aura vs control, migraine with visual aura vs visual and sensory aura vs visual, sensory and dysphasic aura. Significant differences in P100 latencies and N75/P100 amplitudes were found between control and migraine with more than one aura symptom but no differences were found within migraine with aura subtypes. Moreover, in migraine with aura patients positive correlation between visually evoked changes in cerebral blood flow velocities and VEP amplitudes was detected.
  
  
  CONCLUSIONS
  Visual stimulation has significant influence on cerebral blood flow velocities in both migraine with aura patients and controls and these changes are most often observed direct after the beginning of the stimulation. However, no differences in vascular response to visual stimulation between the groups were observed. On the other hand positive correlation between visually evoked changes in cerebral blood flow velocities and VEP amplitudes was found in migraine with aura patients suggesting increased neurovascular coupling in this group when compared with controls.
authors.affiliation: Katedra Neurologii Dzieci i Młodziezy, Uniwersytet Jagielloński Collegium Medicum, Kraków. neupedkr@cm-uj.krakow.pl
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Biedroń
authors.forename: Marek
authors.initials: M
authors.lastname: Kaciński
mesh_terms: D000293:Adolescent; D002560:Cerebrovascular Circulation; D002648:Child; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D008297:Male; D020325:Migraine with Aura / Q000503:physiopathology*; D010775:Photic Stimulation